To the shaw elec



(No Model.) .2 Sheets-Sheet ,1.

A., J. SHAW.

- 'GRANB. No. 528,616.

Patehted No v.,6-, 1894.

(Nb Model.) 2 Sheets-Sheet 2.

A. J. SHAW.

CRANE.

No. 528,616.) Patented Nov. 6, 1894.

U ITED STATES;

PATENT OFFICE.

ALTON J. SHAIV, OF MUSKEGON, MIGHIGAN,ASSIGNOR TO THE SHAW ELEG- TRICCRANE COMPANY, SAME PLACE.

CRANE.

SPECIFICATION forming part of Letters Patent No. 528,616, dated November6, 1894.

Application filed June 7, 1894.: Serial No. 513,846. (No model.)

To all whom it may concern:

Be it known that I, ALTON J. SHAW, a citizen of the United States,residing at Muskegon, in the county of Muskegon and State of Michigan,have invented certain new and useful Improvements in Cranes, of whichthe following is a specification.

My invention relates to cranes, and consists broadly in combining withthe bridge thereof two independent trolleys, eachequipped with hoistingmechanism, one of said trolleys being placed in a higher plane than theother, so. that they may pass and repass without interference, except atsuch times as the hoistingchain of the upper trolley may bedependingwithin the path of the lower trolley.

The invention further consists in a novel construction of the lowertrolley, whereby I am enabled conveniently to place the same within alimited space between the main girders of the bridge.

The object of my invention is to enable the crane more efficiently tohandle and manipulate the loads which it is called upon to carry,

and to permit it to carry separate'and independent loads or objects whenrequired.

In the accompanying drawings,-Figure' 1 is a top plan view; Fig. 2, aside. elevation; Fig. 3, a vertical transverse section of a craneembodying my invention; Fig. 4, a top plan view; and Fig. 5, an endelevation of the lower trolley.

. In the drawingsI have represented the crane as equipped with electricmotors, and such I 3 5 prefer to use, but the invention is in no senserestricted thereto, but covers and includes broadly two independenttrolleys carried by.

the same bridge, one in a higher plane than the other, the two adaptedto move past each other in or upon the bridge. The description thereforewill omit all details as to the construction and arrangement of thedriving 'mechanism, as this may be varied at will and to any extent. Sotoo, the particular manner of constructing and trussing the bridge isimmaterial. Referring again to the drawings, A indicates a' cranebridge, comprising in its construction two longitudinal main girders aa, so here represented as wrought iron or steel plate girders, built upin the usual fashion, with a broad upper and lower plates and ampleangle bar stays or braces. Upon the top of each main girder a a is arail 1) of any approved design, adapted and designed to receive andguide the'truck wheels 0 of a main trolley B, which trolley is designedto traverse the length of the bridge and to run on the top thereof,

where it may receive the full supporting strength of the bridge A. Theends of the girders a a may be connected by truck frames or bridge ends0 of any usual or approved construction, and these may be furnished withtruck wheels d to traverse the rails or tracks of the main runway, as iscustomary at the present time.

Bolted or otherwise made fast to. the inner faces of the main girders aa, are rails e located near the lower chord of said girders, as shown inFig. 3. These rails are designed toreceive and guide truck wheels f of asecond trolley D, which is designed to be of lighter construction thanthe main trolley B, and to travel wholly within the space between themain girders a, or at least at so low a level as readily 7 5 to passbeneath the main trolley B.

The truck wheels of the trolley D being grooved or flanged, and seatedupon the rails e, tend to prevent spreading of the girders a a, and thusthe supplemental or lower trolley subserves in addition to its mainpurpose that of stiifening or tying together the girders of the bridge.This, however, is purely incidental and comparativelyimmaterial, sincethe construction is in all cases such as to in- 8 5 sure the properrigidity and stiffness under all working conditions.

If desired, there may be a plurality of trolleys on the upper track, ora plurality of trolleys on the lower track, or on both, as foundexpedient.

Inasmuch as the running block and chains of the main trolley whendepending from the hoisting drum thereof, would preclude the passage ofthe lower trolley and'restrict its 9 5 travel to the space beyond or atone side of the chain, it will be found convenient in many cases toemploy two of the lower trolleys in order that either may be used atwill according to the location of the worl; to be handled roo thereby.

Where only one trolley is used on the lower track, it possesses materialadvantages over a second trolley placed upon the upper track, because itis possible to bring its hoisting chain and block much closer to thoseof the main hoisting drum than can be done in the case of two trolleyson the main track.

In handling many objects it is important to have in addition to themeans for lifting and carrying the main load, some supplemental means ordevice for tipping, turning, or manipulating the load, or formaintaining its horizontality or any given angle of inclination. In allsuch cases the supplemental trolley is of great importance, and itbecomes especially efiicient when capable of running under the maintrolley and bringing its hoisting chain close to that of the maintrolley. When the two lighter trolleys are provided for the lower track,this facility of work and manipulation is increased, and the efficiencyof the crane as a whole is greatly enhanced.

As above stated, the invention is applicable to trolley cranes of allsorts, whether the bridge be movable or stationary, and whatever maybethe power employed for propelling the machinery, whether electric,pneumatic, steam power, rope transmission, hydraulic, or other.

It is desirable to make the spread or separation of the girders a a asslight as practicable, with due regard to stiffness and strength of thebridge, and when these girders are spaced their ordinary distance apart,it is difficnlt to put the hoisting machinery of the lower trolley insuch compact shape as will enable it to be used entirely within thebridge. I find, however, that this end may be attained by placing thehoisting drum with its length in the direction of travel of the trolley,or in other words, lengthwise of the bridge. This is especiallyconvenient when two hoisting drums are used.

In Fig. 4 I have shown in top plan, and in Fig. 5 in end elevation, atrolley suited for use within the bridge structure.

I am aware that it is not new broadly, to arrange the hoisting drum ordrums of a crane trolley lengthwise of said trolley, or in the directionof its trolley, this idea being very old and common, broadly considered;but by combining this idea with that of placing the trolley whollywithin the bridge or between its main girders, I am enabled to attain auseful result otherwise diflicult if not impossible of attainment. Inall other particulars the trolley may be of any approved description.

Having thus described my invention, what I claim is 1. In combinationwith a bridge or support, two trolleys, each provided with hoistingapparatus and carried by said bridge, one trolley being placed in alower plane than the other, whereby it is adapted to pass beneath saidother trolley, substantially as set forth.

2. In combination with a bridge or support, a main trolley mounted uponthe upper side thereof, and a second trolley mounted within the bridgeor support and adapted to pass beneath the upper trolley, said trolleysbeing each provided with hoisting apparatus.

3. In combination with a bridge or support and a trolley mounted andmovable upon its upper surface, two independent trolleys carried by saidbridge in a plane beneath the main trolley, whereby they are adapted topass under the main trolley and to work on both sides of themainhoisting chain while the latter is in use, each of said trolleys be ingfurnished with hoisting apparatus.

4. In combination with the girders a a of a bridge, provided with railse e, a trolley mounted upon said rails and adapted to travel between thegirders, the hoisting drum or drums in said trolley being arrangedlengthwise of the trolley or in the direction of its travel,substantially as and for the purpose set forth.

In witness whereof I hereunto set my hand in the presence of twowitnesses.

ALTON J. SHAW. Witnesses:

F. W. BABCOCK, T. G. AKIN.

